Control for turbine-driven compressors



Aug. 4, 1953 J. M. DOLAN CONTROL FOR TURBINE-DRIVEN COMPRESSORS 2 Sheets-Sheet 1 Filed Aug. 10, 1945 Aug. 4, 1953 J. M. DOLAN CONTROL FOR TURBINE-DRIVEZN COMPRESSORS 2 Sheets-Sheet 2 Filed Aug. 10, 1945 152/06 1 f011- 7/2. 110 {a u.

Patented Aug. 4, 1953 CONTROL FOR TURBINEFDRIVEN, COMPRESSORS John M. Dolan, Milwaukee,

Wis., assignor to Joy Manufacturing Company, a corporation of Pennsylvania Application August 10, 1945, Serial N 0. 610,001

7 Claims.

fluidto a turbine in accordance with the load on,

a compressor driven thereby.

It is a customary practice to provide valve means for controlling the supply of operating fluid to the inlet nozzles of a turbine so as to obtain an economical operation of the latter under varying conditions of load or to cause it t perate ei-hciently at different desired speeds. Such valve means are made manually adjustable or made to operate automatically in accordance with some changing condition. My invention contemplates the driving of a compressor by a turbine having valve means which may be adjusted man ually or which may be operated by pressure fluid supplied thereto. Thecompressor is providedwith fluid actuated unloading means, and a pilot valve mechanism operates inresponse to the compressor discharge pressures for controlling the flow of pressure fluid'relative to the unloading means and to the valve means at the inlet nozzles of the turbine. valve means are actuated to cut off the supply of fluid to some of the inlet nozzles so as to maintain the pressure at the remaining nozzles and cause the efficiency of the turbine to remain at a value approximately that of full load.

An object of myinvention is to provide an improved control means for a turbine-driven compressor. means for maintaining substantially constant the pressure at the intake of a turbine when the load of a compressor driven thereby is caused to vary. Still another object is to provide a turbine-driven compressor having improved means for cutting oil the supply oi fluid to certain inlet nozzles of the turbine when the compressor is unloaded. Yet another object is to provide improved means for controlling the supply of fluid t the inlet nozzles of a turbine in such a manner that the pressure of the fluid at the intake remains substantially constant as loading and unloading of a compressor driven by the turbine takes place. Other objects of my invention will appear more fully in the following description.

In the accompanying drawing there is shown for purposes of illustration one form which my invention may assume in practice.

In this drawing:

Fig. 1 is a side elevational view of a turbine.

Fig. 2' is an enlarged fragmentary end elevational view taken on the plane of the line 2-2 of Fig. 1 with parts broken away.

When the compressor is unloaded, the

Another object is to provide improved 2 Fig. 3 is a vertical sectional view takenon the plane of the line 3--3 ofFig. 2.

Fig. 4' is a sectional view taken on the plane of the line ir-4 tion.

Fig. 5 is a fragmentary sectional view taken on the plane of the line 5-5 of Fig. 1.

Fig. 6 is a vertical sectional view of a compressor which is connected in driven relation with the turbine of Fig. 1.

Fig. '7 is a sectional View taken on the planes of the line l' l of Fig. 6.

Fig. 8 is a schematic-diagram showing the improved control system for the turbine-driven compressor.

In the illustrative embodiment of the invention there is shown a turbine, generally designated i, having a chamber 2, Fig. 3, to which fluid, such as steam, is supplied under the control of a speed governor, generally designated 3. Partially bounding the chamber 2 is a wall portion 5 having, as shownherein, three pairs of ports lii, 9-46 and i i-i2 connecting the chamber 2 in comniunica on with passages l4, l5 and I6,

of Fig. 3 with parts-inelevarespectively, which communicate through inlet nozzles I 8 with a chamber !9 iii. The ports of each pair are alinement with each other, and cooperating with each pair of ports is a valve member 22 which controls communication between the chamber 2 and the passage into which the ports open. The

containing rotors arranged in axial valve member 22 is connected to a valve stem 23 which carries a piston 25 reciprocably contained within a cylinder 26 attached, as by screws 21, to

to to their closed positions. It will be observed that these two cylinders 26 and their associated pistons 25 constitute servo-motors. It will be appreciated that the number of valve controlled I if desired, varying with the difierent loads that the turbine is expected to carry and the automatic control desired to effect an efficient operation of the turbine. The rotors 20 of the turbine are connected to a shaft 3'! which carries, as shown in Fig. 5, a spur gear 38 meshing with a gear 39 fixed to a shaft 49. A coupling 42, Figs. 1 and '7, connects the shaft 50 to a crankshaft A3 of a compressor, generally designated l5. Fluid supplied through the nozzles to the rotors causes the latter to retate and drive the crankshaft 43 through the shaft 3! and the gears 38 and 39. The fluid is discharged through an exhaust port 46 after per forming Work upon the rotors.

The compressor 45 is shown herein as comprising a casing is having supported thereon a low pressure cylinder 49 and a high pressure cylinder 50. Reciprocable in the cylinders 4e and B are pistons 5i and 52 having piston rods 54 and 55 connected to crossheads 56 and 51 which are reciprocably supported by crosshead guides 58 and 59. Connecting rods El and 62 connect the crossheads 56 and ill in driven relation with a crank arm 83 on the crankshaft 63, the latter being rotatably supported by bearings by the casing 438. Air is taken into the low pressure cylinder through an intake connection 65, shown in Fig. 8, under the control of an intake closure valve, generally designated 87, and air compressed in the low pressure cylinder is discharged through an intercooler 58 to the high pressure cylinder 5i) where it is compressed further and then discharged through a conduit ill to a point of use or to a receiver, not shown.

The intake closure valve ill may be of any standard type and is adapted to be actuated by K pressure fluid supplied thereto for cutting oil the flow of air to the low pressure cylinder and effecting a complete unloading of the compressor. Associated with the low and high pressure cylinders are fluid actuated unloading means it and M which are adapted to unseat inlet valves in the crank ends of the cylinders and effect a part unloading of the compressor. The fluid actuated operating means of the intake closure valve and of the means l2 and it constitute servo-motors. Pilot valves it and '5'? are connected t a conduit l8 communicating with the compressor discharge and operate in response to the discharge pressures for controlling the connection of the compressor unloading means and the control means for the valves of the inlet nozzles of the turbine in communication with the conduit '58 or with the atmosphere. The pilot valve it communicates with the conduit 34 and with conduits to and 8% leading to the unloading means i2 and M, and the pilot valve ll communicates with the conduit 35 and with a conduit 82 leading to the intake closure valve Bl. At a predetermined compressor discharge pressure the pilot valve it operates to connect the conduit "E8 in communication with the conduits 3d, 8d and SI and cause one of the valve members 22 to operate and cut off the supply of operating fluid through the passage l5 to one of the inlet nozzles of the turbine and cause the unloading means l2 and l t to operate and unload the crank ends of the compressor cylinders 9 and 59. When the compressor discharge pressure reaches a higher predetermined value the pilot valve ll operates to connect the conduit :8 in communication with the conduits 35 and 8 2 and cause another valve member 22 to operate and cut off the supply of operating fluid through the passage is to another of the inlet nozzles of the turbine and'cause the intake closure valve 61 to cut 'off'the'flow of air to the compressor 6Q- carried and effect a complete unloading of the latter. When the discharge pressure drops t predetermined low values, the pilot valves 16 and H operate to vent pressure fluid from the operating means for the valve members 22 and from the compressor unloading means, causing the supply of operating fluid to the inlet nozzles to be resumed and a reloading of the compressor to take place.

As a result of my invention there is provided improved means which operate automatically to maintain the efiiciency of aturbine substantially constant while the load of a compressor driven thereby varies. In order that the eificiency of operation may be high at any particular load, the control means for the turbine are made manually adjustable to control the supply of operating fluid to the inlet nozzles. The number of nozzles and control means required will, of course, depend upon the variations in the load to be carried by the turbine.

While there is in this application specifically described one form which the invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration, and that the invention may be modilied and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

l. A mechanism of the character described comprising, in combination, a turbine, a compressor driven by said turbine, inlet nozzles for said turbine, fluid actuated control means for controlling the supply of operating fluid to certain of said inlet nozzles, fluid actuated step unloading means for said compressor, and means operative at difierent predetermined compressor discharge pressures for supplying pressure fluid to different ones of said control means to out said nozzles out in steps and to different steps of said step unloading means.

2. A mechanism of the character described comprising, in combination, a turbine, a compressor driven by said turbine, inlet nozzles for said turbine, fluid actuated control means for certain ones of said inlet nozzles, said control means operative on the supply of pressure fluid thereto for cutting oil the flow of operating fluid to the nozzles controlled thereby, fluid actuated unloading means operative on the supply of pressure fluid thereto for efiecting a step unloading of said compressor, and means operative at different predetermined compressor discharge pressures for supplying pressure fluid to said control means and to said unloading means to cut out nozzles and effect unloading in steps.

3. A mechanism of the character described comprising, in combination, a turbine, a compressor driven by said turbine, inlet nozzles for said turbine, fluid actuated valve means for controlling the supply of operating fluid to certain of said inlet nozzles, fluid actuated step unloading means for said compressor, and means responsive to compressor discharge pressure and operative at diilerent predetermined pressures for supplying pressure fluid to said unloading means to effect a stepped unloading of said compressor and for supplying pressure fluid to said valve means to effect a successive cutting oil of fluid flow to said inlet nozzles.

4. A mechanism of the character described comprising, in combination, a turbine, inlet nozzles for said turbine, means for supplying opcrating fluid to said nozzles, fluid actuated valve means operative on the supply of pressure fluid thereto for cutting olT the supply of operating fluid to certain of said inlet nozzles, pump means connected in driven relation with said turbine and providing a variable load for the latter, and means operative automatically in accordance With pump discharge pressure variations to effect predetermined reductions in the pump load and for concurrently supplying pressure fluid to said valve means in sequence.

5. In combination, a compressor, a turbine connected with said compressor to drive the same, fluid operated means associated with said compressor for partially or wholly unloading it, depending upon the supply of fluid to said fluid operated means, said turbine having a plurality of nozzles, fluid operated means for controlling the flow of fluid through certain of said nozzles, and means governed by compressor discharge pressure for supplying fluid, when compressor discharge pressure is at a predetermined desired maximum to said first mentioned fluid operated means, wholly to unload said compressor and to a plurality of said second mentioned fluid operated means to limit the supply of operating fluid to the turbine to an amount suited to no load conditions, for supplying fluid, when compressor discharge pressure is at or below a predetermined minimum, to none of said first or second mentioned means to cause said turbine to operate with full power and said compressor to operate fully loaded, and for supplying fluid, when compressor discharge pressure is at a predetermined intermediate value, to less than all of said first mentioned fluid operated means and to at least one but less than all of said second mentioned fluid operated means to operate said compressor at normal speed and under partial load.

6. A mechanism of the character described comprising, in combination, a turbine having a plurality of nozzles, at least one of said nozzles having associated with it a servo-motor for controlling the opening and closing thereof, a compressor connected with said turbine for drive thereby, said compressor having associated therewith unloading means including at least one servo-motor, and compressor discharge pressure responsive control means for said servo-motors for causing said at least one servo-motor to effect an unloading operation and said first servomotor to cut out said at least one of said nozzles.

7. A mechanism of the character described comprising, in combination, a turbine having a plurality of nozzles, at least one of said nozzles having a servo-motor for controlling the opening and closing thereof, and at least one other of said nozzles having another servo-motor for controlling the opening and closing thereof, a compressor connected with said turbine for drive thereby, said compressor having step unloading means including an initial step unloading means having at least one servo-motor for efiecting a. partial unloading and another step unloading means having a servo-motor for effecting a further degree of unloading, and compressor discharge pressure responsive control means for said servo-motors for causing said at least one servomotor and said first servo-motor to effect a step of unloading and a cutting out of said at least one nozzle and upon an increase in compressor discharge pressure causing said fourth and second servo-motors to effect a further degree of unloading and the cutting out of said at least one other of said nozzles. JOHN M. DOLAN.

References Cited in the file of this patent UNITED STATES PATENTS 

